fun main() {
    //范围
    //1,2,3,4
    val intRange = 1..4
    println(intRange)
    //1,2,3
    val intRange1 = 1..<4
    println(intRange1)
    //4,3,2,1
    println(4 downTo 1)
    //1,3,5
    println(1..5 step 2)
    // a,b,c,d
    println('a'..'d')

}